1. Field of Invention
The present invention relates generally to data communications, and in particular relates to a method and apparatus for integrating narrowband and wideband data transports to optimize the use of the wideband channel through the effective use of the narrowband channel.
2. Description of the Related Art
The Internet is a rapidly growing communication network of interconnected computers and computer networks around the world. Together, these millions of connected computers form a vast repository of hyperlinked information that is readily accessible by any of the connected computers from anywhere at any time. To provide mobility and portability of the Internet, wireless Internet computing devices were introduced and are capable of communicating, via wireless data networks, with the computers on the Internet. With the wireless data networks, people, as they travel or move about, are able to perform, through the wireless computing devices, exactly the same tasks they could do with computers on the Internet.
Regular mobile phones can return calls, check voice mail or enable users to be available for teleconferences anywhere at any time. However, new two-way interactive communication devices, such as mobile devices or mobile phones, would meld voice, data, and personal digital assistants (PDA) functionality into a single portable equipment that is not just reactive to calls but also proactive, through a proxy computer, accessing a myriad of public and enterprise information services in the Internet. For example, a traveler may request the departure time of a next available flight when on the way to an airport, or a trader may purchase shares of stock at a certain price. The pertinent information from these requests or transactions may include the airline and the flight number for the traveler, as well as the stock name, the number of shares and the price being purchased for the trader. To be timely and periodically informed, one way is to electronically communicate the information requests into a mobile device that is connected to a wireless data network. The wireless data network, for example, connects, through a proxy server, to a flight information server or stock quote server from which the desired flight information or the current stock price can be retrieved by the mobile device on demand.
Alternatively, the traveler or the trader may be preferably informed of any available immediate flight information or a stock price that has hit a pre-set preferred price. It is, however, sometimes disturbing to inform the traveler or the trader of any updated changes to the flight information or the current stock price, especially the stock price being updated every second during trading hours. There is, therefore, a great need for a solution for informing users of any updates to their desired information and allowing the users to retrieve the updated information when needed. Further, in a circuit-switched network, such as GSM, a mobile device must establish a circuit in a carrier infrastructure via a wideband channel before communicating with any server on the network. The connection, similar to a telephone line, can be both time consuming and costly to the users. Hence users generally prefer to have controls over the communication of their mobile devices through the carrier infrastructure when accessing updated information from a web server.
The present invention has been made in consideration of the above described problems and needs and has particular applications to the navigation of Internet web pages using two-way interactive communication devices, such as a mobile device, a mobile phone, a landline telephone, and an Internet capable remote controller.
According to one aspect of the present invention, each of the two-way interactive communication devices, referred to as client devices herein, is a node in a distributed network that comprises the Internet, the Intranet, or other private network along with an airnet. Thus the client devices can access hypermedia information or hierarchic layers or pages of information stored in server devices on the Internet, the Intranet, or other private network via the airnet. When one or more pages of information are updated, users of those client devices subscribing to the updated pages of information receive a notification from one of the server devices that stores the updated information. The notification, depending on an action type therein, upon arriving in the client devices may cause a local cached copy of the corresponding outdated information to be invalidated or to generate an alert message to get immediate attention from the users. Cache coherency is maintained when the users of the client devices navigate to the local cached copy that has been invalidated and causes the client devices to fetch the updated information from the server device.
According to another aspect of the present invention, the client devices communicate with the server devices through a link infrastructure. The link infrastructure, providing an interface between the Internet and the airnet, comprises a link device and a carrier infrastructure. The link device comprises a messenger and a pull engine while the carrier infrastructure comprises a message system (MS), such as a short message service center (SMSC), and an interworking function (IWF). When a notification is sent out from one of the server devices that holds an updated information subscribed by one of the client devices serviced by the link infrastructure, the notification is processed in the messenger to form a corresponding message transportable through MS and possibly IWF depending on whether a communication session has been established. More specifically, the messenger including the notification is coupled directly to MS that is responsible for sending the corresponding message through a narrowband channel to the targeted client device. Upon receiving the corresponding message, the targeted client device is caused to send a request to establish a communication session with the pull engine in the link infrastructure through the wideband channel so as to fetch the updated information from the server that holds the updated information. When the client device is authenticated by the link device, the communication session is established and the updated information is fetched into the link device that further forwards the fetched information to the client device.
Still according to another aspect of the present invention, the messenger comprises a notification manager that assigns a sequence identification to every notification received via the distributed network and a queue list to keep those notifications that could not be successfully delivered. The sequence identification is tractable, such as monotonically and evenly increased numbers, so that each notification is assigned with a unique but tractable sequence number. Similarly, the client device maintains a register to keep the sequence numbers of the notifications received. The sequence number of the last received notification is forwarded to the pull engine in the link device by the client device when the communication session is established. The pull engine consults with the messenger on the forwarded sequence number. If the forwarded sequence number does not match what the notification manager has assigned, which indicates that there are some undelivered notifications in the queue list, the pull engine retrieves those undelivered notifications in the queue list and forwards them to the client device through the wideband channel in which the communication session has been established. With respect to the number of the undelivered notifications received in the client device, the register updates accordingly to prevent the client device to act from the same undelivered notifications that may be forwarded by MS through the narrowband channel.
Still according to another aspect of the present invention, the messenger further comprises an encoder that encodes the corresponding message into a string of alphanumeric characters if MS can only deliver messages of alphanumeric characters. When the corresponding message exceeds the maximum length of messages that MS can deliver, the messenger further includes a message segmenter that segments the corresponding message into a plurality of message fragments and each of the message fragments, preferably sequentially labeled, is respectively and successively sent by MS to the targeted client device. The client device typically proceeds with a reversed process upon receiving the fragments from MS.
Accordingly, an important object of the present invention is to provide a generic solution for informing users of any updates to desired information and allowing users to retrieve the updated information when needed.
Another object of the present invention is to provide a system for systemic solutions for integrating wideband and narrowband channels to keep the users informed of any updates to their desired information and providing efficient means to the users for retrieving the latest updates without incurring uncontrollable costs and increasing unnecessary network traffics.